Systems and methods for direct current system digital carried message conveyance

RELATED APPLICATIONS

0001This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/611,235, filed 17 Sep. 2004, and entitled “Systems and Methods for Direct Current System Digital Carried Message Conveyance.”

FIELD OF THE INVENTION

0002This invention relates generally to digital communication systems. In particular, this invention relates to direct current conductive emissions communications systems.

BACKGROUND OF THE INVENTION

0003Many forms of digital communications used today require separate wires to carry the digital messages from one place to another. The only exception to this trend is RF (Radio Frequency) based systems. Systems employing RF technology transmit a radio signal through the air in the same manner as a cellular phone.

0004When a non-RF system uses dedicated wires for communications, those wires are often referred to collectively as the “communications bus.” A communications bus refers to a group of wires whose responsibility it is to get information from the source to the intended receiver or from the receiver to the source. The reason that is done is to denote the fact that those wires are acting as a stand-alone sub-system and must be isolated from other sub-systems. In more complex systems it is possible to have several communications buses. This would become necessary if the different communications sub-systems were incompatible and the digital information being conveyed by one sub-system would interfere with the operation of another sub-system.

0005<figref idref="DRAWINGS">FIG. 1</figref> is an illustration of a simple prior art communications bus system that might be encountered in a mobile DC (Direct Current) application. This type of system is referred to as using conducted signals or emissions. This means the signal itself is following a conductive path, e.g., a conductive wire of the communications bus. This results in a more controlled message path, a message that can work at low power levels and reduced chances of the signal interfering with other electronic devices.

0006Conducted emission systems to date have had one distinct disadvantage. A conductive path can also carry many types of noise. This noise can come from many sources. Examples would be a motor, solenoid, generator or certain types of lights. Radiated emissions of sufficient power can also attach themselves to a conductive path.

0007One prior art type of communications method that is gaining in popularity is the Radio Frequency (RF) system, as shown in <figref idref="DRAWINGS">FIG. 2</figref>. As explained previously, this works in much the same manner as a cellular phone.

0008RF systems use what is referred to as a radiated transmission or emission. That type of signal is intentionally transmitted into the air surrounding an antenna in all directions. Radiated emission devices are tightly controlled by the FCC (Federal Communications Commission) due to their tendency to interfere with other electronic devices. Conventional RF devices must transmit within well-defined ranges of frequencies that have been established by the FCC. Most of the FCC frequencies require a license to operate a transmitting device. There are specific frequencies set aside for low power devices such as the ones used in the RF devices currently being discussed. These devices collectively are sometimes referred to as “Part 15” devices as that is the section of the FCC rules they operate within.

0009To initiate a RF system, an input device receives information from a pre-determined source. This could vary from a sensor monitoring a certain parameter to a switch sending a “go” or “stop” command. Once the incoming information is recognized, the input controller generates a message for transmission. The input controller would then broadcast that coded message through the air to all other controllers in the system. One disadvantage to this scheme is that any electronic device capable of receiving air-born messages and in close proximity to the transmitting device would also receive the message.

0010In order to minimize the possibility of an unintended device responding to an incoming message the originating controller would encode the message with a special recognition number. To further reduce the possibility of miscommunication, some systems employ what is referred to as a Spread Spectrum Frequency Hopping communications scheme. What that means is that instead of broadcasting on only one frequency, the controller sends out portions of its message on different frequencies. The receiving device must be directed to know what frequency to start at and what other frequencies to hop to as the incoming message progresses.

0011The need remains for simplified digital communication systems and methods that do not require dedicated communications wires and that send digital messages over the same wires that are used to power DC systems.

SUMMARY OF THE INVENTION

0012It is an object of this invention to provide digital communication systems and methods that do not require dedicated communications wires.

0013It is also an object of this invention to provide systems and methods that send digital messages over the same wires that are used to power DC systems, thereby eliminating the dedicated wires and requiring zero additional wires to accomplish the task of digital control.

0014These and other objects of the invention are achieved by providing a communications system comprising an input device and an output device. The input device is coupled to a power source of the load power bus. The output device is coupled to the input device and to a load by the load power bus and to the power source by a return power bus. The output device comprises a filter, a receive detector, a controller, a transmit driver, and a main processor.

0015The filter receives a command signal of a pre-determined frequency transmitted by the input device over the load power bus and filters signals that are not of the pre-determined frequency. The receive detector receives signals from the filter and determines if the signals match the pre-determined frequency and outputs a signal of the pre-determined frequency corresponding to the command. The controller receives the command from the receive detector and processes the command in serial code. The transmit driver is located downstream of the controller and prepares messages received from the controller for injection back into the load power bus. The main processor receives the message from the controller.

0016According to one aspect of the invention, the system is a direct current (DC) system.

0017According to another aspect of the invention, the machine code comprises a group of three Bytes.

0018Objects of the invention are also achieved by providing a conductive emissions communications system comprising an input device, an output device communicatively coupled to the input device by a power line, a load controlled by the output device, and means for transmitting a command signal from the input device to the output device over the power line without the use of a designated communications line. The output device includes means for recognizing the command signal transmitted by the input device, means for filtering interfering signals, and means for controlling the load based on the command signal without the interfering signals.

0019According to one aspect of the invention, the system is a direct current (DC) system.

0020According to another aspect of the invention, the output device includes means for processing the command signal in serial code.

0021Objects of the invention are also achieved by a method of transmitting a digital communication comprising transmitting a command signal directly over a power line from an input device, through an output device, and to a load without the use of a designated communications line. According to one aspect of the invention, the power line is part of a direct current (DC) system.

0022According to another aspect of the invention, the output device includes means for processing the command signal's serial code.

0023According to another aspect of the invention, interfering signals are filtered from the command signal.

DESCRIPTION OF THE DRAWINGS

0024<figref idref="DRAWINGS">FIG. 1</figref> is a schematic drawing of a prior art conductive emissions communications system having a dedicated communications bus for transmitting a signal.

0025<figref idref="DRAWINGS">FIG. 2</figref> is a schematic drawing of a prior art radio frequency communications system.

0026<figref idref="DRAWINGS">FIG. 3</figref> is a schematic drawing of a conductive emissions communications system that permits transmission of a command signal directly over a power bus.

0027<figref idref="DRAWINGS">FIG. 4</figref> is a schematic drawing of a prior art automobile seat control wiring system.

0028<figref idref="DRAWINGS">FIG. 5</figref> is a schematic drawing of an automobile seat control wiring system using the system shown <figref idref="DRAWINGS">FIG. 3</figref>.

0029<figref idref="DRAWINGS">FIG. 6</figref> is a schematic drawing of a prior art automobile mirror control wiring system.

0030<figref idref="DRAWINGS">FIG. 7</figref> is a schematic drawing of an automobile mirror control wiring system using the system shown <figref idref="DRAWINGS">FIG. 3</figref>.

DESCRIPTION OF THE PREFERRED EMBODIMENT

0031Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention.

0032It is useful for the purposes of this disclosure to have an understanding of terms commonly used in reference to communications systems.

0033Serial or Parallel refers to the way in which the information is sent out. In a parallel system, different parts of a message stream are sent over different wires. Computer printers to this day still use a parallel communications scheme. These types of systems can transmit at very high speeds but require many more wires to accomplish the task. In a serial scheme, all of the data is sent out in one stream, one part of the message stacked behind the other. This results in processing at slower speeds but using much fewer wires.

0034Baud rate is the same as the term bps (Bits Per Second). The term baud rate applies to an analog system (i.e., a modem or phone line based system). The term bps refers to a digital system.

0035Twisted pair wires is a term used to describe a method of reducing the influence of external electrical noise on two wires. When you twist two wires together, the strength of the noise riding on the wires tends to be lessened, or attenuated, where the lines cross each other. This is a less expensive way of trying to eliminate noise as opposed to shielded cable. With shielded cable, a conductive foil wrap actually surrounds the wires and is also wrapped over a bare conductor. The bare conductor acts as a drain for the foil shield when one of its ends is connected to ground.

0036Synchronous is a term used to describe when a communications system is controlled by a timing clock. If the system is asynchronous a clock does not control it. The systems and methods of the present invention are preferably synchronous.

0037Bi-directional means the system can send messages in both directions as opposed to uni-directional. The systems and methods of the present invention are preferably bi-directional.

0038Master-Slave or Peer to Peer. These two terms describe whether a system has one controller that is responsible for the control of a communications system (Master-Slave) or if each controller (processor) can access the system (Peer to Peer).

0000I. System Overview

0039In reality all systems in use today, RF or otherwise, attempt to achieve two things: 1) to reduce the number of wires required activating a load of some sort; and 2) moving digital information.

0040An RF system uses a radio message transmitted from an input module to tell a receiver output module what needs to be done or what information is being passed. This in essence, replaces the dedicated communication wires that used to run from the control device, such as a switch, to the controlled load or from one controller to another.

0041<figref idref="DRAWINGS">FIG. 3</figref> illustrates a conductive emissions communications system <b>10</b> that also replaces those same wires and sends information, thereby eliminating the need for dedicated communication bus wires.

0042The system <b>10</b> includes a power source, e.g., a conventional direct current (DC) 12-volt battery <b>12</b>. A load power bus <b>14</b> provides voltage and current from the battery <b>12</b> to an input device <b>16</b> (by way of a series of switches <b>18</b>), to an output device <b>20</b>, and from the output device <b>20</b> to one or more loads <b>22</b>. By way of illustration, in an automobile, a load <b>22</b> may take the form of a light, a motor, a horn, a solenoid, or any other component requiring activation and/or deactivation. A return bus <b>24</b> provides voltage and power back to the battery <b>12</b> from the output device <b>20</b>.

0043Instead of transmitting a signal through the air like a RF system, the system <b>10</b> injects a message or transmitted command <b>26</b> directly onto the load power bus <b>14</b>. That is, the power handling capability of the power bus <b>14</b> is multiplexed in combination with signal transmission. The power and return buses <b>14</b> and <b>24</b> define a two-conductor cable (e.g., black and red) system. Instead of a bundled harness for each command, only the power <b>14</b> and return <b>24</b> cables are required. As only two cables need to be checked/verified or replaced, troubleshooting and diagnostics are greatly simplified.

0044As was discussed earlier, a conductive emissions communications system is more apt to be affected by electrical noise from other devices. One common type of noise is spurious frequency noise. Two different spurious frequency noises, denoted <b>28</b>A and <b>28</b>B to designate different frequencies, are shown in <figref idref="DRAWINGS">FIG. 3</figref>. Burst noise <b>30</b> is normally classified as non-cyclical momentary electrical voltage deviations (positive or negative) and are often referred to as spikes.

0045The output device includes a filter <b>32</b>, a receive detector <b>34</b>, a controller <b>36</b> (e.g., communications chip), a transmit driver <b>38</b>, and a main processor <b>40</b>, which communicate by way of a power line <b>42</b>, which run in parallel to the power line <b>42</b>, thus eliminating bulky series filter elements. Together, these components enable the system <b>10</b> to withstand the burst <b>30</b> and spurious frequency noises <b>28</b>A and <b>28</b>B normally associated with low voltage DC systems.

0046A first group of cooperating components form the filter <b>32</b>, which may be connected via a capacitor to the power line <b>42</b>. The filter <b>32</b> acts to block signals that are not of a desired or proper frequency or that otherwise do not match pre-determined criteria. The filter <b>32</b> is preferably designed to work at a Center Frequency of 1.79 MHz. The Center Frequency is the midpoint of the range of frequencies, or bandwidth, that a filter will pass. This is equal to 1,790,000 Hertz or cycles per second. In a preferred embodiment, the filter <b>32</b> is an arrangement of various components commonly used in filter circuits and available from many manufacturers.

0047A second group of cooperating components form the receive detect network <b>34</b>. The network <b>34</b> monitors signals that have passed through the filter <b>32</b> to determine if they match the desired frequency.

0048A third group of cooperating components form the transmit driver <b>38</b>. The driver <b>38</b> prepares messages from the controller <b>36</b> for injection onto the power line <b>42</b>. In the illustrated and preferred embodiment, the driver <b>38</b> is located on the downstream side of the controller <b>36</b>. After an outgoing signal has passed through the controller <b>36</b>, it is sent back through the filter <b>32</b> and onto the power line <b>14</b> as verification of receipt and transmission of the command signal <b>26</b>.

0049The controller <b>36</b> contains the software that determines if the signal sent through the receive detector <b>34</b> is valid. If it is a valid signal, the information will be decoded and stored in a message buffer. The main processor <b>40</b> is then notified that a new message has come in.

0050The controller <b>36</b> utilizes a communications processor chip along with a specialized circuit board design that minimizes interference found in low voltage DC circuits. In a preferred embodiment, the controller <b>36</b> is a very large-scale integration (VLSI) device, such as model QDC10 available from Yamar Electronic, Ltd., of Tel Aviv, Israel.

0051The controller <b>36</b> and processor <b>40</b> use advanced algorithms to decode and process the command <b>26</b>. All computers are nothing more than a group of switches. These switches can only be either on or off. That being the case there are only two electrical voltage conditions that can exist, energized (Hi) or de-energized (Low).

0052This means that any computer or digital device must communicate in a binary language. A binary language has two characters to work with and the characters are typically 0 (Electrically Low) or 1 (Electrically Hi). No matter how complicated a device may be, it still works with a simple binary language. Binary language is also known as machine code.

0053Processors can only work with a fixed number of 1's and 0's at a time. For many years, processors used blocks of 8 characters of 1's or 0's. An individual 1 or 0 is called a Bit. A collection of 8 bits is called a Byte, 4 bits is called a Half Byte. 16 bits is known as a Word and 32 bits is referred to as a Double Word. In recent years, processors have progressed to the point where it possible to rapidly manipulate 16 bits or 32 bits at a time.

0054Software in each independent electronic module communicates to other modules in a typical system using synchronous (clocked) serial messages. The communications network is bi-directional (sends and receives) in nature. Messages are constructed using a unique “group number” approach. One byte in each message is reserved for a group number. As all messages are broadcast to every module in a system, the group number tells each module if a particular message is meant for that module. The number also pre-qualifies a message for internal processing by the intended recipient. The system format is a combination of Peer-to-Peer and Master-Slave. As with a typical Peer-to-Peer system, each module can transmit a message without direction from the Master. To help prevent collisions on the communications network, each module is assigned a transmit slot number. When a module has a message to send, it must wait for its slot number to come up. The timing for the transmit slot is controlled by an internal timer built into each module. The Master polls the other modules in the system and can override any modules' command in the event of a fault situation.

0055The illustrated system <b>10</b> uses a group of 3 Bytes or 24 Bits of binary information.

0056Example of possible message of the systems and methods of the present invention:

0057<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><thead><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>Byte 1</entry></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="offset" colwidth="77pt" align="left" /><colspec colname="1" colwidth="140pt" align="left" /><tbody valign="top"><row><entry /><entry>1 1 1 1 1 1 1 0</entry></row><row><entry /><entry>Prepare to transmit</entry></row><row><entry /><entry>3 Byte long message</entry></row><row><entry /><entry namest="offset" nameend="1" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0058<tables id="TABLE-US-00002" num="00002"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><thead><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>Byte 2</entry></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="offset" colwidth="70pt" align="left" /><colspec colname="1" colwidth="147pt" align="left" /><tbody valign="top"><row><entry /><entry>0 0 0 0 0 0 1 0</entry></row><row><entry /><entry>Message is for Group 2</entry></row><row><entry /><entry>(On/Off function)</entry></row><row><entry /><entry namest="offset" nameend="1" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0059<tables id="TABLE-US-00003" num="00003"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><thead><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>Byte 3</entry></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="offset" colwidth="63pt" align="left" /><colspec colname="1" colwidth="154pt" align="left" /><tbody valign="top"><row><entry /><entry>0 0 0 0 0 0 0 1</entry></row><row><entry /><entry>Turn “On” Group 2 function</entry></row><row><entry /><entry namest="offset" nameend="1" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

0060The Group format method of message construction not only allows the systems and methods of the present invention to transmit complex messages with a minimum number of Bytes, it also allows for expansion and flexibility beyond the limitations of other message construction techniques.

0061When a message is sent out it has to have a specific target. Normally, this is accomplished by assigning a unique address to each potential target. This is very limiting however, if one of the goals of the system is to keep message length (total number of Bytes) to a minimum.

0062The Group format expands the capabilities of a single Byte of information by accounting for the normally encountered redundancies in most applications. Instead of assigning a specific address to each target, groups are formed of targets that always respond together to a specific command.

0063For example, in an automotive application, both headlights are normally turned on or off at the same time. Instead of targeting a message to each headlight, they can be grouped together so that one group command can operate both headlights. If an operator wishes to turn on only one headlight, the same group number can be used, but the command is changed to turn on only one headlight.

0064As another example, in many hydraulic applications it becomes necessary to activate multiple valves simultaneously. An operator may use the Group format and simply assign each valve grouping a separate group number. If there were a particular valve that is a member of multiple groups, then the processor output terminal for that valve would be assigned all of the group numbers required.

0065The software permits a variety of customized functions to be programmed. For example, lights can be programmed to be flashers or multiple motors may be simultaneously activated to allow a car seat to move forward and up at the same time with one switch. Customized safety features may also be programmed, e.g., to require a designated function or pass code before a switch can be activated. Diagnostics software greatly simplifies troubleshooting. For example, diagnostic functions can monitor loads and broadcast fault conditions to aid in diagnosing short conditions.

0066If increased communication speed is necessary, an additional small processor (not shown) may be provided to act as a buffer between the communications chip <b>36</b> and the main processor <b>40</b>. The additional processor would desirably monitor the communications chip <b>36</b>, store new messages, and transfer messages between the main processor <b>40</b> and the communications chip <b>36</b>.

0000II. Use of the System

0067In use, an operator uses switches <b>18</b> to input a selected function into the input device <b>16</b>. The input device <b>16</b> transmits the command <b>26</b> corresponding to the selected function onto the load power bus <b>14</b> for transmission to the output device <b>20</b>. The command <b>26</b> is a signal transmitted as a pre-determined frequency or frequencies. As <figref idref="DRAWINGS">FIG. 3</figref> illustrates, frequency-based noises <b>28</b>A/<b>28</b>B and burst noise <b>30</b> may also be present on the load power bus <b>14</b> along with the desired command <b>26</b> to the controller <b>20</b> and thereby mask, disrupt, or otherwise interfere with the command signal <b>26</b>.

0068The filter <b>32</b> receives the command <b>26</b> as transmitted by the input device <b>16</b> and filters interfering signals that are not of the pre-determined frequency. The filter <b>32</b> then transmits the “filtered” signals to the receive detector <b>34</b>. In some cases, the filter <b>32</b> may not be able to remove all interfering noises. For example, <figref idref="DRAWINGS">FIG. 3</figref> illustrates a situation in which the filter <b>32</b> has removed the burst noise <b>30</b> and frequency-based noise <b>28</b>B. However, the filtered signals still retain frequency-based noise <b>28</b>A along with the command signal <b>26</b>.

0069The receive detector <b>34</b> receives the signals from the filter <b>32</b> and determines if the signals match the pre-determined frequency corresponding to the command signal <b>26</b>. In the illustrated example, the receive detector <b>34</b> recognizes that the noise <b>28</b>B does not correspond to any pre-determined frequency and disregards the noise signal <b>28</b>B. The receive detector also recognizes the command signal <b>26</b> as corresponding to a pre-determined frequency and outputs the command <b>26</b> to the controller <b>36</b>.

0070The controller <b>36</b> receives the command <b>26</b> from the receive detector <b>34</b> and decodes and processes the command <b>26</b> in binary language comprising a Group of three Bytes, as previously described. The controller <b>36</b> then transmits the confirmed message to the main processor <b>40</b>.

0000III. Representative Applications

0071One of the significant features of the systems and methods of the present invention is the relative ease of custom configuration for varied applications in multiple markets. The systems and methods of the present invention are built on a modular design platform so many applications can be accomplished with minimal development time. The system <b>10</b> is inherently reliable through the utilization of commonly used components.

0072Automotive:

0073Mainstream: At the time of manufacturing, vehicles may be equipped by the manufacturer with individual controls and indicators for security systems, interior &amp; exterior lights, sound &amp; video systems, climate control, and various options available on the vehicle.

0074Aftermarket: Available in standard modules, customers (e.g., car rebuild shops, actual end-users) may purchase the modules they need for their specific requirements. Modules would be designed to interface with aftermarket “kits” so that features like electric windows, security systems and custom lighting could be easily added to older vehicles. Modules would also interface with aftermarket or original equipment monitoring and control systems.

0075<figref idref="DRAWINGS">FIGS. 4 and 5</figref> are illustrative embodiments of automobile seat control wiring. <figref idref="DRAWINGS">FIG. 4</figref> illustrates a conventional prior art system employing a multiplicity of additional dedicated wires. <figref idref="DRAWINGS">FIG. 5</figref> illustrates use of the system <b>10</b> of the present invention to eliminate the need for interconnecting load control wires. In the embodiment illustrated in <figref idref="DRAWINGS">FIG. 5</figref>, the control module serves as the output device <b>20</b> and the door panel control center serves as the input device <b>16</b>. The system <b>10</b> may also be interfaced with DVD, Stereo/Radio, and security systems.

0076<figref idref="DRAWINGS">FIGS. 6 and 7</figref> are illustrative embodiments of automobile mirror control wiring. <figref idref="DRAWINGS">FIG. 6</figref> illustrates a conventional prior art system employing a multiplicity of additional dedicated wires. <figref idref="DRAWINGS">FIG. 7</figref> illustrates use of the system <b>10</b> of the present invention to eliminate the need for interconnecting load wires. The control module serves as the output device <b>20</b> and the mirror control center serves as the input device <b>16</b>.

0077Specialty Truck:

0078Municipal: Switch inputs, indicators, and joysticks for controlling snow plows, salt spreaders, augers, lift mechanisms, and specialty lighting including strobes &amp; emergency lights may be installed. The advantages over existing systems are: reduced installation time, significantly smaller in size (cab space), simplified trouble shooting, increased control capability, and improved performance.

0079Forestry Equipment:

0080Logging: The described systems and methods are well-suited for installation on vehicles and equipment used in processing lumber and log-handling. The typical wire harnesses used to operate the various mechanisms are very complex and can be difficult to troubleshoot. The systems and methods of the present invention reduce cost, simplify wiring requirements, improve system reliability, and increase operator control.

0081Agriculture:

0082The systems and methods of the present invention can be used to control the application of fertilizers and weed control liquids, hydraulics, pneumatics, pumps, seed dispensing equipment, and crop harvesting devices. With simplified wiring systems, equipment dealers can install the systems and methods of the present invention at the factory or at the dealership. Troubleshooting is greatly simplified with primary checkpoints at the controls and the modules.

0083Redundant System Applications:

0084The systems and methods of the present invention can be installed in addition to existing systems and used as a primary or backup in applications such as:

0085Aviation:

0086The simplicity and size (weight) of the systems and methods of the present invention provide a primary or backup electrical system for controls and indicators. By connecting to the system bus, the systems and methods of the present invention can be installed with existing systems and utilized as necessary. The reliability and lightweight components of the systems and methods of the present invention provide distinct advantages over conventional systems.

0087Recreational Vehicles:

0088As the complexity of a recreational vehicle's electrical system increases, the need to reduce wire harness weight and assembly time becomes more acute. The systems and methods of the present invention are ideally suited to help accomplish these goals. One example would be the use of multiple control panels connected to a power bus running the length of the vehicle. Interior lights and other devices controlled at the front of the vehicle could also be controlled at other locations in the vehicle requiring only the two wires in the power bus.

0089Marine:

0090Boats need to be as lightweight as possible to increase top end performance, reduce fuel consumption and increase cargo capacity. If a boat is loaded with features, the systems and methods of the present invention could reduce the number of interconnecting wires by 40% or more. The use of software to mimic complicated switch or relay controls can reduce the overall part count and total system cost.

0091Mobile Equipment:

0092Cranes, bulldozers, road graders, and other pieces of equipment that use large banks of electro-hydraulic valves could benefit from a less complex wire harness.

0093The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention.